_By D. Richard Hipp on 2003-09-03:_

I propose a new built-in function for SQLite to be used for doing full
text searches.  The function would look like this:

_: search(PATTERN, ARG1, ARG2, ...)

The first argument is a pattern containing one or more space separated
words to search for.  The function returns a score based on how well
the pattern matches the arguments.  The score is increased by 100 for
every whole-word match and is increased by 1 for every subword match.

By "whole-word" match, I mean that a word from PATTERN
matches a complete word in one of the arguments.  A subword match is when
a word in PATTERN is part of a longer word in the arguments.  For example,
if a PATTERN contained the word "IS" and an argument contained the
words "WISHFUL" then the "IS" would have a subword match against
"WISHFUL" because "IS" is contained within "WISHFUL".

Because of difficulties dealing with case in international character
sets, case would be significate for these comparisons.  If you want
to do a caseless search, surround each argument with a lower() function
call.  Or, perhaps there should be a separate function named
search_nocase(...)?

_By Matt Sergeant on 2003-09-03:_

I prefer to see this sort of thing kept out of the database. It's fairly easy to implement full text 
search using either a few extra tables, or a separate database (see the perl module DBIx::
FullTextSearch for an example). I don't see a reason to add this to sqlite.